Submarine signaling



H. C. HARRISON.

SUBIVIARINE SIGNALING.

APPLICATION FILED 11:1Y.12.1919.

Awjh l Patented. Mar. M, 1922.

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ED STATES ATENT QFFICE.

HENRY O. HARRISON, or PORT WASHINGTON, NEW YORK, AssIGNoR To WESTERNELECTRIC COMPANY, INCORPORATED, or NEW YORK, N. Y., a CORPORATION NEWYORK.

SUBMARINE SIGNALING.

Specification of Letters Patent.' Patented R131'. 14, 1922.

Application filed July 12, 1918. Serial No. 316.458.

' State of New York, have invented certain new and useful Improvementsin Submarine Signaling, of which the following is a full,

' clear, concise, and exact description.

i conditions.

This invention relates to submarine signal.

ing and more particularly toa device for detecting or receivingvibrations in the waterk set up by submarine signaling apparatus or bythe movement of a submarine vessel in neighboring waters.

In connection with detecting apparatus for submarine signaling systemsand more particularly detectors for giving warning of the proximity ofenemy submarine vessels. it is of importance that the apparatus be ofhigh sensitivity in order to be operated satisfactorily by the feeblevibrations propagated through the water. Not only is it of importancethat the apparatus be highly eiicient initially but it is also necessaryto insure that this efiiciency is not impaired as the result of longimmersion or otherwise appreciably affected by changes in' operating indetectors employing a diaphragm, one side of which is in contact withthe water, more or less trouble has been experienced due to the'hydrostatic pressure acting upon the diaphragm when the apparatus issubmerged. This pressure tends to how the diaphragm inward, thus makingit less Isensitive to vibrations and if a fm icro..v

phone unit is attached to thel diaphragm, the carbon granules arepressed together causing packing which still further decreases thesensitiveness of the instrument. Again, withV a device of this type inwhich the diaphragm is acted upon by hydrostatic pressure, a

. chailge of head due to the action of waves may cause sufficientmovement of the diaphragm to make the device noisy and thereforeunsatisfactory for thework in hand.

It is the object of the present invention to provide a device of highsensitivity for the detection of under-water vibrations and to soarrange the parts that the sensitivity of the instrument is not affectedby hydrostatic pressure exerted upon the diaphragm. A further Object ofthe invention is to provide a device in which movement of the diaphragmdoes not-result from the change of head due to wave action.

Avibrating diaphragme adapted to respond in uniso These and otherfeatures of the inventionl will be more clearly understood by referenceto the accompanying drawing inwhich l 1 is a sectional view of adetecting device embodying the features of this inventiongFig. 2 is asectional view of a modification of the device shown in Fig. 1 butequipped with a plurality of microphone units; and Fig. 3 is va partialview showing the arrangement of the transmitter buttons as employed inthe device of Fig. 2.

Referring now to'these drawings, there is provided a disc-shapedmounting or casing 5. which is preferably of bronze to withstand theaction of the salt Water. The central portion of this mounting isprovided with an opening 6 inwhich the microphone unit is mounted andthesides of this opening are closed by the diaphragms 7 and 8. A mountingplate 9 of hard rubber or similar insulating material is secured bymeans of the screws 10,-10 to the annular shoulder portion 11.- Thecentral portion of this mounting plate is provided with a threadedOpening adapted to receive the metal bushing 12 which in turn isprovided with an Opening to receive the stem 13 of a transmitter buttonof the ordinary type. A set screw 14 threads into the bushing 12 andbears against stem 13 to hold the button securely in position. The frontelectrode 15 of the transmitter button is secured by means of the nut 16to support 17 and riveted or otherwise secured to'this support is aU-shaped member 18 -whichis adapted to bear against preferably of ringsof soft rubber` are fitted in depressed portions in the casing againstwhich the diaphragms are firmly clamped b means of the clamping rings24-24 whic are held in place by means of the screws 25-25. Soft rubberrings 26-26 are inserted between the diaphragms and the clamping ringsas shown. The upper portion of the casing is provided with an opening toreceive the conducting cable 28, a stuling box 29 being provided, asshown, to prevent the en trance of water alon this cable.

The structure of ig. 2 differs from that of Fig. 1 in that threemicrophone elements Y 30, 31 and 32 are'mounted 120 apart on theinsulating mounting plate The front electrodes of these units aresecured to a spider or support 34, thehnb portion of which is adapted tothread onto a post 35. The ends of post 35 are formed to tit withinsimilarly shaped depressions in the diaphragms 36 and 3,7.

'In both of the structures described, the two diaphragms are rigidlyconnected together at their centers in such a manner that thehydrostatic pressure exerted on one diaphragm tends to counterbalancethe similar pressure exerted on the other diaphragm, thereby preventingmovement of the diaphragms due to change in hydrostatic pressure, orother changes acting equally on opposite surfaces lof the diaphragms.

What is claimed is:

l. A vibration responsive device comprising a disc-shaped mounting platehaving an opening centrally located therein, -a pair of flexiblediaphragms closing the ends of the opening, means 'for compelling thediaphragms to vibrate in unison, and means responsive to the vibrationof one of said diaphraglns to vary the electrical characteristics .of acircuit.

2. A vibration responsive device comprising a disc-shaped mounting platehaving an opening cent-rally locatedtherein, a pair ot flexiblediaphragms closing the endsof the opening, means for compelling thediaphragms 'to vibrate in unison, and a transmitter button rigidlyconnected to the mounting plate and having its movable electrode inoperative relation with one of said diaphragms.l

3. A vibration responsive device comprising a disc-shaped mounting platehaving an opening centrally located therein, a pair ot' flexiblediaphragms closing the ends of the opening, means for compelling thediaphragms to vibrate in unison, and a plurality of transmitter buttonsarranged in operative relation with one of said diaphragms.

In ,witness whereof, l hereunto subscribe my name this 3rd day of July,A. D., 1919.

HENRY c. HARnisoN.

